Refining apparatus for crude oil



April 30, 1935 J P: BQHAN 5 L 1,999,954-

REFINING APPARATUS FOR CRUDE OIL v Filed Ap ril 5, 1952. Y 2 sheets-Sheer;

Iii-B071 an n ump April 30, 1935. J; P. BOHAN ET AL I REFINING APPARATUS FOR CRUDE OIL Filed April 5, 1932 '2 Sheets-Sheet 2 Wafer Wa tz/I4 7'0 ,sforaye Kerosene zfik'ora e 70.5 lz ne 7:5 5 74.76

9 FBohmn Patented Apr. 30, 1935 UNITE-D s'rArss REFININ G APPARATUS FOR CRUDE OIL John P. Bohan and Thomas P. Bohan,

. Louisville, Ky.

Application April 5, 1932, Serial No. 603,335

This invention relates to a system of separating various marketable products such as gasoline, naphtha and kerosene from crude petroleum oil, and particularly to a system which accomplishes this result without employing either extreme high pressure or temperature.

One of the main objects of the invention is to provide an apparatus or still of thischaracter which is small and maybe erected. in an oil field whose continued production is doubtful so that in the event the field should fail, the apparatus may be easily disassembled, moved and reerected economicallyin another producing field. vA further object of the invention is to provide asystem of this character which'is automatic and may be operated by semi-skilled labor, thus securing a greater profit from a given quantity of crude oil than is possible with the stills atpresent in use.

Another object is to provide aan apparatus of this character which since it does not employ extreme temperatures nor extreme pressures shall be considerably cheaper'to build than the ordinary apparatus used.-: 7

Another object is'to secure the result desired without the use of high temperatures and pressures, which act to scorch and cake the oil, thus eliminating frequent shut-downs to clean out the caked and charred heavier semi-solids from the apparatus. V

A furtherobject is to provide a system of this character in which the flow of oil through the apparatus is entirely controlled by means of the pump which initially pumps the oil into the first tower of the apparat Other objects will appear in the course of the following description.

Our invention is illustrated in ing drawings, wherein:

Figure l is a vertical sectional view of the main portion of the apparatus, the heaters 2 of the beaters being shown in elevation;

Figure lais a diagrammatic sectional view of the condensers read in connection with Figure 1; "Figure 1b is a diagrammatic sectional view. of the indirect heater for the last tower of the series and is to be read in connection with Figthe accompanyure 1;

Figure'Z is a diagrammatic elevation of the steam supplying furnace, boilerand allied parts. The drawings are largely diagrammatic and in these drawings ll], Illa and' "lb indicate towers.

The crude oil is pumped from the supply pipe ll by means ofthe pump l2 to the pipel3 which 6 Claims; (01. 196-'106) I reflux condenser M in the top of the tower llh It will be understood that hot vapors arising through this tower It], as will be later stated, and the crude oil being cold willcause a small 5 amount of these hot vapors in the tower It to condense and fall back in the tower and assist in the separation of the naphtha 'from the oil sprayed in the tower. From the reflux condenser It, theoil is carried by pipe l5 into the reflux condenser Na in the tower Illa and, of course, absorbs heat from the vapors arising in this tower 18a and causes the condensation of a portion of these vapors. From the reflux condenser Ma, the oil fiows by pipe i6 to the lower end of the tower I lie and into the coil ll which is immersed in the heavy hot oil accumulated in the bottom of the tower ma. Here the oil in the coil ll receives heat that would otherwise be' wasted. From the coil ll, the oil flows by means of'pipe 18 to a refluxcondenser Mb in the upper end of the. towerv !0b where the condensing and heating operation is again repeated. From thereflux condenser Mb, the oil flows by means of pipe i9 into the inner pipe 2E: of a heat. exchanger designated generally 2|. This heat exchanger consists of the convoluted inner pipe'20 V and outer connected pipes surrounding the convoluted pipe 26 and connected to a source of hot oil. From the innerv pipe 29 of the heat'exchan'ger 29,- the oil is carried by. pipe 22' to the'tower l0 and is sprayed into the middle of this tower 'by a spray pipe 23. Above this spray pipe isa bed of gravel 24 supported upon a' perforated septum 25 and below this spray pipe 23 there is a layer of gravel 26 supported by means of the perforated septum 21. The crude oil fiowing'from the pipe 20 through the heat exchanger 2| is raised to a temperature of 22D F.

When the oil from the heat exchanger is sprayed into the tower l8 by the sprayer 23, the temperature of the toil is such that the lighter elements immediately turn" into vapor and flow upward through the upper bed of gravel 24 while the heavierelements remain in liquid form and 45 flow down through the lowerbed of gravel -26. The objectof these two beds-oi gravel 24 and'26 is to assist in separating all the lighter elements possible from the heavier elements inthe crude oil. The lighter elements flowing upward-as vapor'through the upper bed of gravel are washed free of any heavier elements that might be mixed with them. This washing or cleaning effect is 7 obtained by the reflux secured by the reflux condenser l4. From the tower I0, these vapors are 55 conducts this oil into the led by pipe 28 to the condensing coil 29 in the condensing tub 36 which is filled with cold water and the vapor is condensed into liquid form as gasoline and is discharged into a gasoline storage tank by the pipe 3|.

The heavier elements which fall through the bed of gravel 26 and into the lower portion of the tower l6 are retained therein as a relatively deep pool of hot oil and from time to time pumped therefrom by means of the pump 32, this pump being led to a pipe 33 and the passage of steam is controlled by the valve 34.. This valve 34 in turn is controlled by a float 35 in a float chamber 36 connected at its upper and lower ends to the upper and lower ends of the space beneath the plate 21 in tower Ill. The pump 32 pumps the oil from the lower end of tower I6 into a second heat exchanger designated generally Zla and of the same character as the heat exchanger 2|. The outer tubes of this heat exchanger are connected by a pipe 36 to the main steam pipe 31 which conducts steam to the pipe 33.-

. The pipe 31 is connected to the outer pipe of heat'exchanger 210. by means of an automatic pressure control valve 38. Thus the temperature of the oil leaving the heat exchanger 21a is raised to and definitely and accurately controlled at approximately 325 F. by predetermining the pressure of the steam in the. outer pipe of the heat exchanger am. From the inner tube of the heat'exchanger 2|a, the oil at a temperature of 325 F. is carried by means of a pipe 39 into the middle of the tower Illa and is sprayed down ward in this tower through the lower bed of gravel 26a, the vaporized portion of this highly heated oil rising upward through the upper bed of gravel 24a. The vapors are discharged through thepipe 49 to the condensing coil 29a disposed within the condenser 36a and from the coil 29a, the liquid such as gasoline, benzine, etc., is carried off to storage by the pipe 3|a. The unvaporized portion of the oil discharged through the pipe 36 passes down through the bed of gravel 26a and into the lower end of the tower |6a where it acts to heat the coil H as previously described. From the lower end of the tower llla, this oil is pumped away by the pump 4|. The steam for this pump is'provided by the pipe 42, the passage of the steam being controlled byvthe valve 43 'in turn; controlled by a float 44, the float chamber being connected to the upper and lower ends of the space beneath the bed of gravel 26a. The pump 4| pumps the liquid accumulated in the lower end of the tower |6a into the pipe 45 and into a coil 46 which is disposed in a furnace 41.

This is an intermediate heating furnace, theinterior of which is divided by a fire wall 48 into two compartments, the compartments opening into each other at their upper ends.

In one of these compartments, the coil 46 is disposed and in the other compartment, there is provided a crude oil burner illustrated diagram: maticallyand designated 49. By providing acombustion compartment and a tube compartment in this furnace 41, better combustion .is obtained, the heat is more evenly distributed and the coil 45 not exposed to the scouring action ofan open flame. The fuel preferably used' in the burner 49 is crude oil left after the gasoline, naptha and kerosene have been removed. The burner 49. is of a conventional steam atomizing type, the steam flow remaining constant while the fuel supply to the burner is increased or decre se b means of the. centroliing. valve 50 in turn controlled by a thermostat in the oil line 52, which leads from the oil 46. In this heater, the oil is raised to approximately 450 F. and is then discharged through the pipe 52 and sprayed into the interior of the tower I0b where a separating action again takes place as in the towers I6 and la. The vapors from the tower |0b are led by the pipe 53 into the condensing coil 29!) and the liquid from the condensing coil is carried to a kerosene storage tank by means of the pipe 54. The heavier elements fall in the bottom of the tower I62) and through the gravel beds 24b and 26b and are pumped through the outer coils of the heat exchanger 2| by means of the pump 55, this pump being controlled by the valve 56 in turn controlled by the float 51 whose float chamber is connected to the upper and lower ends of the space below the gravel bed 26b. From the outer coils of the heat exchanger, the oil is carried by pipe 58 to a storage tank as fuel oil.

The steam supplied through the pipe 31 to the pumps 32, 4| and 55' is secured from a high pressure steam boiler designatedgenerally 59 heated by an oil burner 66 of the same general character as the oil burner 49 previously referred to. The boiler feed water is pumped to the boiler by means of the pump 6|, the steam from which is taken from the boiler by the pipe 62 controlled by. a valve 63 in turn controlled by a float 64, the float chamber of which communicates with the upper and lower portions of the boiler. Pressure in this boiler is maintained by means of the pressure controlling, valve 65 which in turn controls the valve 66 which controls the flow of fuel to the burner, thereby controlling the intensity of, the fire. Throughout the entireapparatus whenever. any heat exchange is made, the counter-fiow principle is used, that is to say the element to be heated, enters the apparatus where the heating element is coolest and leaves it where the heating element is hottest.

Each step of this apparatus is kept in time with the step preceding it by means ofthe float controls 35, 44, 51 and these float controls maintain a constant predeterminedlevel in the bottom of each of the separating towers l0, la and I01) and retain at the lower end of each tower a relatively deep pool of hot oil. The entire apparatus is controlled by, means of the master pump l2 and since all of the operations are automatic if the pump I2 is slowed down or speeded up the remainder of the apparatus will automatically adjust itself to increase or decrease within the capacity of the apparatus..

Cold water may be supplied to the condensing tubs for the condensers 24a, 24b, and 240 in any suitable manner as for instance the pump 61.

It will be seen from the figures that pipes 68 are associated with each tower whereby steam may be dischargedinto the base of each tower below the lower bed of gravel, this steam aiding in heating the condensing liquid as the steam rises through the tower.

The fuel used in the burners 49 and 60 is fuel oil left after the kerosene naptha and gasoline have been removed from the crude oil. In this way after the apparatus has once been started no outside source of fuel is necessary. The steam flow to both of these burners remains constant but the fuel supply to the burner is increased or decreased by means of the controlling valves as set forth, changingthe flow of fuel oil to secure anydesired variation in heat output of the burners. The water condensate in the outer coils of the heat, exchangers 2| a, is carried off by means of thesteam trap 69 or in any other suitable manner.

We claim: a r

1. A petroleum distilling apparatus including a series of counter-fiow towers, each heated to a different temperature and each having a charge preheating coil in its upper end, means for conducting oil at a relatively low temperature success'ively through the several coils from the coil "in the tower of least temperature to the coil in the tower of highest temperature, means for spraying the petroleum flowing from the last coil'of the series in the tower of higher temperature into the first and coolest tower of the series whereby to separate the vapor from the liquid, means for pumping the oil collected in the lower end of each tower of the series except the last tower into the next tower of the series and spraying it thereinto, means for pumping the liquid from the last tower of the series, each of the pumps associated with the towers having controlling means therefor in turn controlled by the level of the liquid in thecorresponding tower, means for carrying off and separately condensing the vapors from the several towers, means for heating the liquid in any one tower to a predetermined degree before it is sprayed into the next succeeding tower, means for using liquid taken from the lower end of the last and hottest tower of the series as a heating medium in heating the transfer apparatus for the oil passing into the first and coolest tower of the series, means for using steam at a constant pressure and temperature as aheating medium in the transfer apparatus for the oil passing from the first and coolest tower of the series into the second tower thereof, and means for heating the oil from the next to the last tower to a predetermined temperature.

2. A petroleum distilling apparatus including a series of towers, each heated to a different temperature and each having a charge preheating coil at the upper end thereof, means for conducting relatively cool oil from a source successively through the several coils from the coil in the tower of least temperature to the coil in the tower of highest temperature, heat transferring apparatusthrough which the oil for the last coil of the series is conducted, a pump connected to the last tower of the series and discharging liquid from the bottom of this tower into the heat transferring apparatus, means for controlling said pump in accordance with the liquid level in the last tower of the series, means for conducting oil from said heat transfer apparatus to the first tower of the series and spraying said oil downward through the tower to thereby separate the lighter fractions from the liquid, a second heat transfer apparatus, means for conducting steam at a predetermined pressure through heat transfer apparatus, a pump taking oil from the lower end of the first tower of the series and forcing the oil through the heat transfer apparatus and into the second tower of the series, a float actuated by the level of liquid in the first tower of the series for controlling said last named pump, means for spraying the oil downward through the second tower of the series whereby to separate the vaporized fraction from the liquid, a pump receiving oil from the lower end of the second named tower, float operated means associated with the second named tower for controlling the operation of said second named pump, a heater, the pump discharging liquid into said heater, the other end of the heater having a pipe discharging into and spraying the liquid' down into the third tower of the series. F 3. A method of separating fractions frompetrol'eum consisting'in conducting the charge. of petroleum at a constant speed successively through reflux coils in the upper ends of a series of counter-flow towers, each tower of the series being heated to a higher degree than thetower immediately'preceding it, carrying the oil through the refiux coil of an intermediate tower of the series into a coil disposed in the base ofthe said intermediate tower, then conducting the oil too, reflux coil in the upper end of a final tower, heating the oil flowing from'this final coil to a temperature of approximately 220 F., spraying it into the first tower of the series to permit the separ'ationin said tower of the lightest fractions from the petroleum, pumping off the liquid from the lower end of this first tower at a constant rate and simultaneously heating the liquid to'a temperature of 325 F., spraying this liquid at this temperature into an intermediate counterflow tower to separate the gasoline fractions, pumping off the liquid in the lower end of the last named tower and forcing it at a constant speed through a furnace and raising it in this furnace to a temperature of 450 F., discharging the oil so heated into and spraying it downward through a third counter-flow tower to separate the kerosene fractions from the remainder of the oil, carrying off and separately condensing the vaternperature of the said furnace to maintain said temperature constant.

4; A petroleum'distilling apparatus including a series of towers each-heated to a different temperature, each having a charge preheating reflux condensing coil therein, the condensing coils being connected in series with a steam operated master pump and being disposed successively in towers of increasing temperature, means for heating the petroleum before it passes into the condensing coil of the last tower of the series, means for heating the petroleum after it passes through the coil in the last tower and spraying it into the first tower of the series, a steam operated pump for each tower of the series except the last and taking liquid from the bottom of one pors from'the several towers, and controlling the tower and spraying it into the next tower of the series, means for highly heating the petroleum immediatelybefo-re its discharge into the last tower of the series,- a pump for the last tower discharging liquid from the bottom of the tower, all of said pumps having a common source of steam, and means controlled by the level of liquid in each tower for controlling the passage of steam to the corresponding pump.

5. A petroleum distilling apparatus including a series of counter-flow towers each having a charge preheating reflux condensing coil therein, the condensing coils being connected in series with a source of relatively cold crude petroleum and a master steam pump, means for heating the petroleum before it passes into the condensing tower of the series taking liquid from the bot- 1 tom of this tower and discharging it for storage,

of said pumps having acommon source of 'liquidin the lower end of each tower controlling the admission of steam to the corresponding pump.

6. A method of refining crude petroleum oil which consists in pumping the crude petroleum at a constant rate successively through a series of reflux condensing coils in the upper ends of a series of counter-flow towers to thereby preheat the oil, spraying the oil from the last tower of the series downward through the first tower of the series at a temperature of approximately 220 F., pumping off the liquid from the bottom of the first tower, heating the liquid so pumped off to approximately 325 Rand discharging it into the second tower, pumping off the liquid from the bottom of the second tower, raising-its temperature to approximately 450 F. and discharging it into a third tower separately carrying off and condensing the vapors from all these towers, pumping off the liquid from the third 1:

tower of the series, controllingthe several pumps associated with the several towers in accordance with the level of the liquid in the bottoms of the several towers to thus maintain pools of constant depth in the bottom of the towers and utilizing the hot liquid at the bottom of the second named tower to heat the oil passing to the reflux condenser of the third named tower and utilizing the liquid from the bottom of the third named tower to heat the oil sprayed into the first named tower.

JOHN P. BOHAN. THOMAS P. BOHAN. 

